Growth in spending on prescription drugs in the US slowed to 3.2% in 2008, continuing a decelerating trend that began in 2000, according to new government figures.

However, prescription drug prices increased 2.5% during the year, compared with a rise of just 1.4% the previous year which had been due to the number of branded drugs losing patent protection from mid-2006. Despite the faster growth in 2008, the level for the year still remains below recent rates, with annual growth in prescription drug prices having averaged 4.1% during 1997-2007, according to economists from the Centers for Medicare and Medicaid Services (CMS), reporting this morning in the journal Health Affairs.

Prescription drug spending growth linked to non-price factors such as use and intensity also decelerated for the year, as per capita use of prescription medicines dipped slightly due to the recession, plus a dip in the number of new product launches and growth in safety concerns, they note.

In 2008, spending growth for healthcare overall in the US slowed to 4.4%, the slowest rate of rise in the last 48 years, say the government officials. Nevertheless, national health spending reached $2.3 trillion - $7,681 per person – during the year, and the percentage of Gross Domestic Product (GDP) devoted to health care increased to 16.2%, from 15.9% in 2007.

The US economy was in recession for the whole of 2008, and GDP grew at a slower rate than total health spending, say the CMS officials, who add: “despite the overall slowdown in national health spending growth, increases in this spending continue to outpace growth in the resources available to pay for it.”

The recession was also likely responsible for the relatively widespread failure of patients to get their prescriptions filled; significant numbers of people were also reported to be skipping doses or splitting pills, the report notes.

Growth in sales of new drugs decelerated in 2008, for reasons including the fact that many newly-approved drugs were indicated for low-prevalence conditions or did not represent major therapeutic gains, while sales data were also skewed by the large number of products introduced late in the year. In addition, safety concerns had negative effects on the use of osteoporosis treatments, hormone replacement therapies and erythroid stimulants, while “black box” safety warnings were added to products in a number of widely-used therapeutic classes, and there were a number of product withdrawals.